Raising a family is one chapter in your lives. Make the decisions/sacrifices/changes/committments to do it right. You only get one chance.
Here's one possible way: move out to the country, so that you can set a housing budget that does not require two salaries. With your mate, look at your relative strengths and desires, and adjust your work lives to get the income you need and not more. Spend the rest of the time with your kids. Give work travel to your colleagues with no kids, stay home. It's just 15 years, you've got plenty of career after this chapter is over.
Also, to have two parents available, you need to not get divorced. Which means in addition to keeping you kids healthy you have to protect your relationship from degrading.
Good luck!